Abstract: In accordance with the present invention, there are provided cells for expressing recombinase Cre in the presence of recombinase FLP in a FLP-dependent manner, methods of expressing recombinase Cre by introducing recombinase FLP into the above cells, methods of producing recombinant viral vectors using cells that express recombinase Cre in the presence of recombinase FLP in a FLP-dependent manner, and methods of producing recombinant adenovirus vectors using the above method of producing Cre and the above method of producing recombinant viral vectors.

Abstract: In accordance with the present invention, there are provided cells for expressing recombinase Cre in the presence of recombinase FLP in a FLP-dependent manner, methods of expressing recombinase Cre by introducing recombinase FLP into the above cells, methods of producing recombinant viral vectors using cells that express recombinase Cre in the presence of recombinase FLP in a FLP-dependent manner, and methods of producing recombinant adenovirus vectors using the above method of producing Cre and the above method of producing recombinant viral vectors.

Abstract: An animal cell is co-transfected with both a recombinant DNA viral vector which bears a promoter, a recombinase gene and a poly(A) sequence and a recombinant DNA viral vector which bears two recombinase-recognizing sequences and which further bears an origin of replication, a promoter, a foreign gene and a poly(A) sequence, each of which is located between the two recombinase-recognizing sequences. Thereafter, in the co-transfected animal cell, a DNA fragment containing the origin of replication, promoter, foreign gene and poly(A) sequence is excised from the vector by the action of a recombinase expressed in the another vector. The DNA fragment forms a circular DNA molecule which autonomously replicates in the co-transfected animal cell due to the origin of replication, whereby the foreign gene is continuously expressed.

Abstract: Disclosed are a recombinant adenovirus bearing a DNA sequence encoding a desired foreign polypeptide, and a hybrid promoter (CAG promoter) comprising a cytomegalovirus enhancer, a chicken .beta.-actin promoter, a rabbit .beta.-globin splicing acceptor and a polyA sequence, a process for production thereof, as well as use thereof for in genetic treatment. The recombinant adenovirus effectively expresses the foreign polypeptide in a wide range of animal cells.

Abstract: A recombinant DNA virus for transfecting an animal cell and bearing a foreign gene and a promoter capable of regulating expression of the foreign gene is completely deleted of the function of E2A gene. The recombinant DNA virus can thus stably transduce the foreign gene into various animal cells, which leads to continuous expression of the foreign gene in the animal cells. The continuous expression of the foreign gene can provide an effective treatment of hereditary disease.